First stage pressure regulators for underwater breathing convert high pressure gas to a lower pressure at or near a pressure that can be breathed by a diver. The high pressure gas is generally supplied to the first stage pressure regulator from an outlet of a cylinder of compressed air at a pressure that may be in excess of 4,000 psi.
The high pressure gas is received by the first stage pressure regulator through an orifice of the first stage pressure regulator into a high pressure chamber of the valve body of the first stage pressure regulator. Orifice sizes, hardness, and sealing surfaces contribute to the efficiency and amount of high pressure air passing into the high pressure chamber of the valve body. Heretofore, the high pressure gas has been received into the high pressure chamber of the valve body through an orifice formed into and of the valve body.
Such high pressure receiving orifices that are integral with the valve body have resulted in complex and time consuming machining of the first stage pressure regulating valve body. Additionally, because the orifice is integral with the valve body the hardness of the outer sealing edges of the orifice is limited to the same material and hence the same hardness of the valve body itself. Accordingly, the sealing edge of the orifice has proven difficult to protect from wear. Further, it has been difficult to protect such an integral orifice from corrosion because its location within the valve body makes it difficult to coat with anti-corrosion materials. Still further, quality control of the integral valve body orifice must be done with the valve body itself as opposed to being able to do quality control of the orifice independent of the valve body. Moreover, maintenance of such orifices has proven difficult since its wear is wear of the valve body itself.
The present invention seeks to provide improvements over the current state of the art of first stage pressure regulators for underwater breathing devices. These and other advantages of the invention, as well as additional inventive features, will be apparent from the description of the invention provided herein.